[PATCH] USB: add apple usb touchpad driver

This is a driver for the USB touchpad which can be found on post-February 2005
Apple PowerBooks.

This driver is derived from Johannes Berg's appletrackpad driver [1],
but it has been improved in some areas:
    * appletouch is a full kernel driver, no userspace program is necessary
    * appletouch can be interfaced with the synaptics X11 driver[2], in order
      to have touchpad acceleration, scrolling, two/three finger tap, etc.

This driver has been tested by the readers of the 'debian-powerpc' mailing
list for a few weeks now and I believe it is now ready for inclusion into the
mainline kernel.

Credits go to Johannes Berg for reverse-engineering the touchpad protocol,
Frank Arnold for further improvements, and Alex Harper for some additional
information about the inner workings of the touchpad sensors.

Signed-off-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 84 insertions, 0 deletions

diff --git a/Documentation/input/appletouch.txt b/Documentation/input/appletouch.txt
new file mode 100644
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+++ b/Documentation/input/appletouch.txt
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+Apple Touchpad Driver (appletouch)
+----------------------------------
+	Copyright (C) 2005 Stelian Pop <stelian@popies.net>
+
+appletouch is a Linux kernel driver for the USB touchpad found on post
+February 2005 Apple Alu Powerbooks.
+
+This driver is derived from Johannes Berg's appletrackpad driver[1], but it has
+been improved in some areas:
+	* appletouch is a full kernel driver, no userspace program is necessary
+	* appletouch can be interfaced with the synaptics X11 driver, in order
+	  to have touchpad acceleration, scrolling, etc.
+
+Credits go to Johannes Berg for reverse-engineering the touchpad protocol,
+Frank Arnold for further improvements, and Alex Harper for some additional
+information about the inner workings of the touchpad sensors.
+
+Usage:
+------
+
+In order to use the touchpad in the basic mode, compile the driver and load
+the module. A new input device will be detected and you will be able to read
+the mouse data from /dev/input/mice (using gpm, or X11).
+
+In X11, you can configure the touchpad to use the synaptics X11 driver, which
+will give additional functionalities, like acceleration, scrolling, 2 finger
+tap for middle button mouse emulation, 3 finger tap for right button mouse
+emulation, etc. In order to do this, make sure you're using a recent version of
+the synaptics driver (tested with 0.14.2, available from [2]), and configure a
+new input device in your X11 configuration file (take a look below for an
+example). For additional configuration, see the synaptics driver documentation.
+
+	Section "InputDevice"
+        	Identifier      "Synaptics Touchpad"
+	        Driver          "synaptics"
+		Option          "SendCoreEvents"        "true"
+		Option          "Device"                "/dev/input/mice"
+		Option          "Protocol"              "auto-dev"
+		Option		"LeftEdge"		"0"
+		Option		"RightEdge"		"850"
+		Option		"TopEdge"		"0"
+		Option		"BottomEdge"		"645"
+		Option		"MinSpeed"		"0.4"
+		Option		"MaxSpeed"		"1"
+		Option		"AccelFactor"		"0.02"
+		Option		"FingerLow"		"0"
+		Option		"FingerHigh"		"30"
+		Option		"MaxTapMove"		"20"
+		Option		"MaxTapTime"		"100"
+		Option		"HorizScrollDelta"	"0"
+		Option		"VertScrollDelta"	"30"
+		Option		"SHMConfig"		"on"
+	EndSection
+
+	Section "ServerLayout"
+		...
+		InputDevice	"Mouse"
+		InputDevice	"Synaptics Touchpad"
+	...
+	EndSection
+
+Fuzz problems:
+--------------
+
+The touchpad sensors are very sensitive to heat, and will generate a lot of
+noise when the temperature changes. This is especially true when you power-on
+the laptop for the first time.
+
+The appletouch driver tries to handle this noise and auto adapt itself, but it
+is not perfect. If finger movements are not recognized anymore, try reloading
+the driver.
+
+You can activate debugging using the 'debug' module parameter. A value of 0
+deactivates any debugging, 1 activates tracing of invalid samples, 2 activates
+full tracing (each sample is being traced):
+	modprobe appletouch debug=1
+		or
+	echo "1" > /sys/module/appletouch/parameters/debug
+
+Links:
+------
+
+[1]: http://johannes.sipsolutions.net/PowerBook/touchpad/
+[2]: http://web.telia.com/~u89404340/touchpad/index.html